The present invention relates to a fastening device. More particularly, but not exclusively, this inventions concerns a fastening device for fastening a first part to a second part. The invention also concerns the fastening of a first part to a second part, where at least one of the first part and second part includes a manufacturing tolerance, and the fastening device at least partially adapts to this tolerance.
Many components in an aircraft are made out of composite materials, such as carbon fibre reinforced plastic, or glass fibre reinforced plastic. Aircraft also often comprise components made of metal. When joining a component made of a composite material to a component made of metal, it is desirable that any coupling between the two components is such that the coupling stress is reduced. This is particularly advantageous for composite components, which when loaded, or stressed, in certain directions may be vulnerable to damage or failure. Additionally, composite components are usually made with at least one datum face, with a closely controlled profile, and a non-datum face, where manufacturing tolerances may exist. When a composite component is joined to a metal component, the non-datum face is may be in contact with the metal component, meaning that there may be a gap between at least part of the contact surfaces between the composite component and metal component. Simply tightening a bolt through the composite component and metal component may act to close this gap, thereby potentially deforming the datum face of the composite component and also stressing the composite component. This may lead to damage or failure of the composite component, thereby requiring replacement or repair, and increasing aircraft maintenance time and cost.
The paragraph above describes joining a composite component to a metal component. However, the problems raised by manufacturing tolerances may be even more pronounced when joining together two composite components.
The present invention seeks to mitigate the above-mentioned problems. Alternatively or additionally, the present invention seeks to provide an improved fastening device.